Buying in bulk from warehouse clubs like Costco, BJ's, and Sam's Club, can net you significant savings. There are some products in particular, though, that you're better off not buying in bulk—namely: soda, office supplies, and household paper products.

Forbes reports that you can get bigger savings at the local grocery store for these products than you can get at the warehouse club:

When it comes to grocery store discount specials, anything that customers purchase on a weekly or monthly basis is fair game. Retailers either offer them at a loss, hoping to make up the difference elsewhere in the shopping basket, or work with suppliers to defray the costs on a promotional basis. In general, warehouse clubs don't play the high-low pricing game, but supermarkets do, and that's where you can reap the savings.

This applies to soda, as well as toilet paper, and if you couple the weekly promos with coupon-clipping, you'll save the most possible. Another "savings experiment," by Wallet Pop, confirms that toilet paper and paper towels are best bought at the supermarket when they're on sale—during the first week of the month and mid-month.

Buying office supplies (e.g., copy paper) in bulk also doesn't pay off, according to Forbes. So, to summarize, you'll need to supplement your warehouse club shopping with grocery store and/or office supply store stops to get the most savings. Photo by AgentAkit.